What good is parental leave if no one uses it? Cities including San Francisco and New York recently passed mandatory paid family-leave legislation, yet most U.S. workers still rely on employers to provide the benefit. These new laws are awesome … but societal norms still need to catch up.

The IT industry likes to tout its progressive, innovative nature. Companies such as Google, Facebook, Twitter and Apple all publicize their generous parental leave policies, as well as their intentions to increase the numbers of women and underrepresented minorities in their ranks.

Both of these initiatives, in theory, sound fantastic, and they're long overdue. In practice, however, things don't necessarily work out for the better … at least not for women. As pointed out by Bloomberg.com reporter Rebecca Greenfield, so few women work in technology anyway, and societal norms tend to penalize female and male employees alike when they take parental leave, so the only parties that benefit are the tech companies.

An old adage comes to mind: If it sounds too good to be true, it probably is.

These programs are great for companies that want to trumpet their progressive natures and use parental leave as a recruiting and hiring tool. Unfortunately, many of these companies know that their mostly male workforces won't take advantage of the full scope of available leave, or they likely suspect women will feel pressured to shorten their leave — or not take any — for fear of repercussions.

It's fantastic that Silicon Valley companies are leading the charge for more generous parental leave policies. But behind all the PR spin and joyful proclamations of progressive policies, more systemic and fundamental change is still needed.